1. Field of the Invention
This invention relates generally to eye position movement. In particular, this invention relates to a helmet mounted eye tracker which monitors the eye position movement of the cornea of the human eye.
2. Description of the Prior Art
Heretofore, numerous oculometers and other eye-tracking apparatus have been employed to monitor the eye position movement of the human eye. Such systems of the prior art are too numerous to discuss herewith. Besides most thereof constitute prior art devices which are well known to the artisan, thereby obviating the need for further discussion thereof.
Of course, there are several prior art devices which are of some significance, inasmuch as they at least remotely or indirectly concern subject matter that is pertinent to the apparatus constituting the instant helmet mounted eye tracker using a position sensing detector.
For example, U.S. Pat. No. 3,462,604 to K. A. Mason discloses an oculometer for determining the orientation of an eyeball by measuring the position of the image of light reflected from the retina of the eye relative to the position of the image reflected from the front surface of the eye.
U.S. Pat. No. 3,473,868 discloses an eye measuring instrument employing a modulated invisible light source which illuminates the eye, and a pair of photocells directed to the interface of portions of the eye with different light reflecting properties. The interfaces selected move in response to eye movement or pupil area change, and the changes in the photocell outputs are a measure of the eye movement or pupil area change.
U.S. Pat. No. 4,145,122 to G. A. Rinard et al discloses an apparatus for monitoring the position of the eye, and for generating an electrical signal based upon the eye's displacement from a neutral position. The apparatus is characterized by a pair of eyeglasses modified to provide an infrared mirror on the inside surface of one lens, an infrared light emitting diode located on the nosepiece in position to produce a virtual image thereof within the wearer's eye as reflected from the infrared mirror, and an image detector mounted on the bow of the eyeglass adjacent the mirror filtered to respond only to infrared light and effective to locate the position within the eye of the reflected light emitting diode image.
Unfortunately, the aforementioned devices of the prior art ordinarily leave something to be desired, especially from the standpoints of position measurement accuracy and response time; that is, the aforementioned devices of the prior art do not allow for position measurement at high rates. In addition, the aforementioned devices of the prior art do not operate in exactly the same manner as the subject invention and contain a combination of elements that is somewhat different from that of the present invention.